<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
     .red{
        color: red;
     }
     .font20{
        font-size: 20px;
     }  
    </style>
</head>
<body>
    <div class="red font20">多类名</div>
    <div>多类名</div>
    <div>多类名</div>
    <div>多类名</div>
    <p class="red">多类名</p>
    <p>多类名</p>
    <p>多类名</p>
    <p class="red">多类名</p>
    <div>多类名</div>
</body>
</html>